Hydrogeological Impacts of Urbanization

Urbanization creates hydrogeologic changes of significance both at the local scale and at larger scales. Urbanization and urban sprawl are projected to increase in the coming century, which will alter the corresponding groundwater systems both physically and chemically. Changes include the covering of shallow subsurface systems, (generally) increasing recharge from leaky utility systems and irrigation return flow, dramatic changes to subsurface secondary porosity and permeability from utility systems and other construction, the effects of imported water resources, and groundwater and soil contamination from point and non-point sources, storm-water control systems, and both modern and legacy pollution from urban development. Understanding of these changes, their causes, and their effects is necessary to addressing the critical and growing environmental and water resource issues of urban areas in the coming century.